Post hole digger



Dec. 13, 1966 A. E. KAMMER 3,291,231

POST HOLE DIGGER Filed Dec. 29, 1964 INVENTOR.

M23550 ,6", XGVVMALZ United States Patent 3,291,231 POST HOLE BIGGERAndrew E. Kammer, 407 Eldert Lane, Brooklyn, N.Y. Filed Dec. 29, 1964,Ser. No. 421,800 3 Claims. (Cl. 175--170) This invention relates to adevice for digging holes in the ground, particularly post holes or thelike.

It is the principal object of this invention to provide a tool ofimproved design for forming cylindrical holes to a desired depth ofdesired proportions with ease and a minimum of labor, which does notpack the earth and which provides a post receiving hole of optimumdimensions with a minimum of soil handling.

Another object of this invention is to form the tool device as acylindrical metal sleeve provided with a circumferential row .of earthcutting teeth at the lower edge of the sleeve, the upper end of thesleeve having formed therein diametrically opposed reverse bayonet-slotsto removably receive a handle bar for operating the sleeve by rotatingthe same clockwise to effect its cutting function.

A further object of the invention is to provide interiorly of the sleeveand adjacent the cutting teeth a pair of diametrically opposed angularlyrelated cutting blades that function to cut-out and support the earthcore that is cut out by the device.

A still further object of the invention relates to the removal of thecut out earth core by the simple expedient of turning the sleeve upsidedown on its removal from the earth upon completion of its cuttingoperation by a counter-clockwise rotation, with the earth core containedtherein, and simply dropping the earth core therefrom.

Further objects of the invention will appear as the descriptionproceeds.

To the accomplishment of the above and related objects, my invention maybe embodied in the form illustrated in the accompanying drawings,attention being called to the fact, however, that the drawings areillustrative only, and that change may be made in the specificconstruction illustrated and described within the scope of the appendedclaims.

FIGURE 1 is a perspective view of the digging device with handle barpositioned thereon.

FIGURE 2 is a vertical sectional view of the digging device taken online 2-2, FIGURE 1, showing the sam in use.

FIGURE 3 is a bottom view of the digging device.

FIGURE 4 is a perspective view of one of the cutting blades.

FIGURE 5 illustrates the manner of discharging the earth core from thedigging device.

Referring to the drawings, the post hole digging device consists of acylindrical metal sleeve 12 having an outside diameter corresponding tothe diameter of the post selected for use, it being understood that thedigging device 10 may come in a variety of sizes each corresponding tothe size of post used. Preferably the sleeve 12 is formed of sheet steelof a thickness of inch, and may be of any desired length. For generalpurposes, a length of 30 to 36 inches has been formed to be satisfactoryfor the sleeve 12, as Well as diameters of 4, 5 and 6 inches.

The sleeve 12, at its lower terminal end, is provided with acircumferential row of teeth 14 of a size and shape that will readilycut into the earth. Preferably the teeth 14 are deflected slightlyradially outwardly, as shown, so as to cut a kerf in the soil of adiameter slightly greater than the diameter of the sleeve 12. This willprevent binding of the sleeve in the soil and will facilitate the easyremoval of the sleeve from the soil upon the completion of the cuttingoperation.

The upper end of the sleeve 12 has formed therein a pair of bayonetslots 16 and 18, arranged diametrically opposite each other andreversely related, that is, the bottom horizontal portions of thebayonet slots extend 1n opposite directions. Adapted to removably fitwithin the bayonet slots 16, 18 in a handle bar 20, the intermediateportion thereof being engageable within the bayonet slots, as shown inFIGURES 1 and 2.

A pair of like cutter blades 24, 26, are located interiorly of thesleeve 12 adjacent the teeth 14. Referring to FIG- URE 4, it is seenthat the blade 24 consists of a blade portion 30 and a flanged orbracket portion 32. The blade portion 30 is formed flat and is providedwith a transverse cutting edge 34 at its forward end. The rear end 36 ofthe blade is narrower than the front end. The outer side 38 of the blade24 is curved to correspond with the cylindrical curvature of the sleeve12, and depending from the curved side is the bracket portion 32 whichis also correspondingly curved. Provided in the bracket portion 32 areopenings 40 for receiving fastener elements such as rivets. The blade 26is formed similar to the blade 24. Both blades 24 and 26 are positionedsubstantially diametrically opposite each other and are each inclineddownwardly towards the teeth 14 along a helical path in order tofacilitate their entry and downward movement through the earth onclockwise rotation of the sleeve 12.

The blades 24, 26 are so positioned that their leading cutting edges 34are located slightly (not more than 4 inch) above the base of the sawteeth 14 as shown in FIGURE 2. Referring to FIGURE 3, it will be seenthat the straight side edge 39 of each blade opposite its curved bracketportion 32 will in the attachment of the cutting blades to the sleevelie parallel to each other and that the vertical plane of the cuttingedge 34 of each blade will intersect the straight side edge of the otherblade. The transverse cutting edge 34 of each blade provides the leadingedge thereof as shown in FIGURE 3. The blades 24, 26 are each secured tothe inside wall of the sleeve 12 by rivets 43. If desired, the blades24, 26 may be welded direct to the sleeve 12.

With the handle bar 20 in position on the sleeve 12, a post hole is dugby the sleeve 12 when placed on the soil 46, see FIGURE 2. Rotation ofthe sleeve in a clockwise direction and the application of downwardpressure on the handle bar 20 will cause the saw teeth 14 to cut a kerfin the soil. Downward movement of the sleeve 12 thus effected willsubsequently cause the blades 24, 26 to enter the soil and progressdownwardly in a helical path until the desired depth of hole is reached.The blades 24 and 26 function to break off the bottom of the core orplug of earth formed in the sleeve such that removal of the sleeve 12with its core is easily effected by an upward pull on the handle baraccompanied if necessary, by rotating the sleeve counter-clockwise. Oncomplete removal of the sleeve 12 from the soil, there is left therein acylindrical hole for the reception of the post, and-the core or plug 48is simply dropped out of the sleeve 12 when it is turned up-side-down asshown in FIGURE 5.

While certain novel features of my invention have been shown anddescribed and are pointed out in the anneXed claims, it will beunderstood that various omissions, substitutions and changes in theforms and details of the device illustrated and in its operation can bemade by those skilled in the art without departing from the spirit ofthe invention.

Having described my invention, what I claim as new and desire to secureby Letters Patent is:

1. A post hole digger device comprising:

(a) a cylindrical sleeve for coring, retaining and releasing soil,

(b) a circumferential row of cutting teeth on the lower terminal end ofsaid sleeve,

(c) at least one cutting blade interiorly of said sleeve having acutting edge adjacent the base of said cutting teeth,

(d) a handle bar removably connected to the upper end of said sleeve,

(e) said cutting teeth are each deflected outwardly of the outercylindrical surface of said sleeve, and

(f) the removable connection of said handle bar with said sleevecomprising a pair of diametrically positioned reverse bayonet slotsformed in the upper end of said sleeve and opening into the upperterminal end of said sleeve, whereby said handle bar is insertedhorizontally simultaneously into both bayonet slots and retained thereinby a slight turning movement,

(g) a fiat blade portion,

(h) a curved bracket portion corresponding in curvature to the insidecylindrical wall curvature of said sleeve,

(i) a leading cutting edge on said blade portion extending transverselythereof, and

(j) means rigidly securing the bracket portion of said cutting blade tothe inside wall of said sleeve.

2. The post hole digger of claim 1, wherein:

(a) The fiat blade portion fthe cutting blade is inclined downwardlytowards the cutting teeth such as to move downwardly into the soil alonga helical path on clockwise rotative movement of said sleeve,

(b) said cutting blade being operative to cut the bottom of the earthcore from the earth whereby to permit removal of the sleeve and corefrom the soil.

3. The post hole digger of claim 2, wherein:

(a) a pair of cutting blades are located within said sleeve and disposedin diametrically opposed relation with the leading cutting edge of eachfacing opposite portion of the inside wall surface of said sleeve,

(b) the rear edge of each blade portion being narrower than the leadingcutting edge thereof, and

(c) the side edge of each blade opposite the curved bracket portionthereof being straight,

(d) whereby in the attachment of said cutting blades to the inside wallof said sleeve, said straight side edges of said blades will lieopposite each other in parallel relationship and the vertical plane ofthe leading cutting edge of each blade will intersect the straight sideedge of the other blade.

References Cited by the Examiner UNITED STATES PATENTS 2,708,593 5/ 1955Benoist 29450.7 2,854,219 9/1958 MacNeil 1754O4 FOREIGN PATENTS 5,419 5/1879 Germany.

HUGO O. SCHULZ, Primary Examiner.

GERALD M. FORLENZA, Examiner.

G. F. ABRAHAM, Assistant Examiner.

1. A POST HOLE DIGGER DEVICE COMPRISING: (A) A CYLINDRICAL SLEEVE FOR CORING, RETAINING AND RELEASING SOIL, (B) A CIRCUMFERENTIAL ROW OF CUTTING TEETH ON THE LOWER TERMINAL END OF SAID SLEEVE, (C) AT LEAST ONE CUTTING BLADE INTERIORLY OF SAID SLEEVE HAVING A CUTTING EDGE ADJACENT THE BASE OF SAID CUTTING TEETH, (D) A HANDLE BAR REMOVABLY CONNECTED TO THE UPPER END OF SAID SLEEVE, (E) SAID CUTTING TEETH ARE EACH DEFLECTED OUTWARDLY OF THE OUTER CYLINDRICAL SURFACE OF SAID SLEEVE, AND (F) THE REMOVABLY CONNECTION OF SAID HANDLE BAR WITH SAID SLEEVE COMPRISING A PAIR OF DIAMETRICALLY POSITIONED REVERSE BAYONET SLOTS FORMED IN THE UPPER TERMINAL OF SAID SLEEVE AND OPENING INTO THE UPPER TERMINAL END OF SAID SLEEVE, WHEREBY SAID HANDLE BAR IS INSERTED HORIZONTALLY SIMULTANEOUSLY INTO BOTH BAYONT SLOTS AND RETAINED THEREIN BY A SLIGHT TURNING MOVEMENT, (G) A FLAT BLADE PORTION, (H) A CURVED BRACKET PORTION CORRESPONDING IN CURVATURE TO THE INSIDE CYLINDRICAL WALL CURVATURE OF SAID SLEEVE, (I) A LEADING CUTTING EDGE ON THE SAID BLADE PORTION EXTENDING TRANSVERSELY THEREOF, AND (J) MEANS RIGIDLY SECURING THE BRACKET PORTION OF SAID CUTTING BLADE TO THE INSIDE WALL OF SAID SLEEVE. 